1. Field of the Invention
This invention relates to a locking device for doors, windows or the like, which is applicable more particularly to fittings for doors, windows or the like.
2. The Prior Art
As a rule, a house door is locked by means of a casement lock either mortised in the edge of the jamb of the movable frame of the door, or fastened to the main surface thereof. This casement lock comprises a mechanism transmitting the movement impressed to the handle to locking means such as a half-turn bolt or a plurality of bolting members somewhat spaced from each other and connected to the mechanism by means of control rods. These casement locks comprise in general a cylinder lock actuated by means of a key and driving a fixed bolt. The various locking means comprising the bolts, the half-turn bolt and the dead bolt are actuated by a particularly complicated mechanism which increases considerably the cost of the casement lock.
On the other hand, casement locks are also known which comprise a half-turn bolt and/or a plurality of bolts or locking members somewhat spaced from the casement bolt case and actuated by control rods. All the bolt members are retracted only by means of a handle, not by means of a handle plus the key of a cylinder lock, as in the case of a casement lock.
In frequent cases the above-mentioned casement locks or casement bolts are used for closing and locking doors and may also be used for closing windows.
However, the two types of locks mentioned hereinabove are attended by various inconveniences.
Casement locks, as already mentioned, are relatively complicated and therefore expensive. The complexity of their component elements is also likely to reduce the useful life of the locking means.
On the other hand, in the case of casement bolts, it is possible to open the door, window closure or the like from outside by actuating the bolts thereof. These bolts are rigidly connected to rods and can easily be released from the keepers or striker plate fastened or formed on the fixed jamb of the frame by simply hooking the bolts and pulling them down to their release position. If the casement bolt comprises only a single half-turn bolt, a simple tool of any kind is sufficient for retracting and recessing the half-turn bolt, in case the latter is adapted to rotate about an axis, and it is also possible to retract the half-turn bolt by rotating it through a half-turn in the opposite direction.
A backward movement of the locking member is attained almost automatically by the rotation of the control handle. It is therefore advisable to lock this handle against rotation and thus present any actuation of the locking members.
For this purpose, a handle has already been proposed which incorporates a locking device. As a rule, this handle is relatively bulky in cross section since all the component elements of the locking device must be enclosed therein. For the sake of convenience, this handle has the appearance of a round-sectioned knob. However, this arrangement for locking a door or window is applicable only to a well-defined handle construction and therefore restricts the choice of a handle from the dual point of view of shape and type. On the other hand, the relatively large cross-sectional area of the handle may also prove detrimental, notably in case the frame of the door or window has a relatively narrow jamb.
It is the essential object of the present invention to avoid the above-described inconveniences.